Anaerobic digestion enhancement with microbial electrolysis cells: is biomethane production the direction to go for commercialization?

The engineering of replacements for crude oil is a priority within industrial biotechnology. Biogas, produced by anaerobic digestion (AD) during organic waste degradation, has been used for electricity generation and heating. Microbial electrolysis cells (MECs) are an emerging technology which when combined with AD can produce higher yields of such energy whilst simultaneously treating waste water and sludge. MECs are bioelectrochemical systems which utilize the metabolism of microbes to oxidize organics. The majority of the research has been focused on biohydrogen production, despite associated issues, which has resulted in poor commercialization prospects. Consequently, scientists are now suggesting that methane production should be the focus of MEC technology. This chapter presents lab research on the bioprocessing of biomethane using AD and MECs and addresses important issues, namely the lack of pilot-scale studies. Downstream processing techniques are discussed, as well as a novel suggestion of further utilising MECs in the purification process.